1. Field of the Invention
The present invention relates to a gate driver circuit applicable to an inductive load such as a motor, or the like, an inverter module, and an inverter apparatus.
2. Description of the Related Art
In general, in order to supply a driving signal to an inductive load used in an electric product such as an electric vehicle, or the like, an inverter converting a DC voltage into an AC voltage may be used, and in order to drive the inverter, a gate driver generating a gate signal is required. Here, the inductive load may include a motor, a heating coil, and the like.
In general, an inverter includes a high side switch and a low side switch to generate an AC voltage. The high side switch and the low side switch are complementarily switched in each phase, and an insulated gate bipolar transistor (IGBT) element may be used as the high side switch and the low side switch.
The gate driver includes a high side driver IC (e.g., high voltage integrated circuit (HVIC)) for driving the high side switch and a low side driver IC (e.g., low voltage integrated circuit (LVIC)) for driving the low side switch.
The inverter and the gate driver may be configured as an IC, respectively, and manufactured as a single inverter module, and a pad of the gate driver and a pad of the inverter may be connected through a wire or a lead frame. Such an inverter module may be mounted on a printed circuit board (PCB) to form a PCB board assembly (PBA).
When a PBA is designed by using an inverter power module (hereinafter referred to as an ‘inverter module’), the following matters should be taken into consideration. First, in order to drive a high side IGBT operable at a high voltage, a potential difference greater than an emitter terminal by an amount equal to a turn-on voltage should be made between a gate terminal and the emitter terminal of the high side IGBT. Also, when a low voltage (e.g., 0V) is applied to the emitter terminal (connected to a VS terminal), a turn-on voltage may be applied to the gate terminal (connected to an H0 terminal and a VB terminal), but when a high voltage (e.g., 300V) is applied to the emitter terminal, a voltage (e.g., 300V+ turn-on voltage) higher than the high voltage by an amount equal to the turn-on voltage should be applied. To this end, a bootstrap capacitor is required between the VB terminal and the VS terminal of the high side driver IC (i.e., HVIC).
Here, however, the VB terminal and the VS terminal are formed on the opposing sides, so in order to connect the bootstrap between the two terminals, a line connected to the VB terminal is required to be formed up to the VB terminal formed on the opposite side to connect the bootstrap capacitor, complicating a PCB design and increasing the size of the PCB.
Thus, a lead frame of the inverter module or a pattern on a substrate are lengthened and complicated, and since a space between the substrate and the board is increased, the design of the substrate is complicated, and due to the complicated lead frame and pattern, noise is highly likely to be introduced.
Patent document 1, the Prior art document below, relates to an inverter driving apparatus for controlling a behavior of a brushless DC (BLDC) motor applied to an electric vehicle using a 42V power system. However, this document does not disclose technical matters regarding an addition of a VS pad in designing a high side driver (i.e., an HVIC) aimed at simply manufacturing a PCB or technical matters regarding positions in which an added VS pad and VB pad are formed.